diff --git a/Source/cmakemain.cxx b/Source/cmakemain.cxx
index 3da5a06924..1a5d2dbce3 100644
--- a/Source/cmakemain.cxx
+++ b/Source/cmakemain.cxx
@@ -82,6 +82,9 @@ static const cmDocumentationEntry cmDocumentationOptions[] =
   {"--graphviz=[file]", "Generate graphviz of dependencies.",
    "Generate a graphviz input file that will contain all the library and "
    "executable dependencies in the project."},
+  {"--debug-trycompile", "Do not delete the try compile directories..",
+   "Do not delete the files and directories created for try_compile calls. "
+   "This is useful in debugging failed try_compiles."},
   {"--help-command cmd [file]", "Print help for a single command and exit.",
    "Full documentation specific to the given command is displayed."},
   {"--help-command-list [file]", "List available listfile commands and exit.",